Journal of Performance of Constructed Facilities

The Structural Engineering Institute of the American Society of Civil Engineers Committee on the Reliability-Based Design of Wood Structures recently completed a special project entitled “The next step for ASCE 16: Performance-based design of wood structures.” This paper presents the methodology and several illustrative examples of the design of residential wood-frame buildings for flood. The control variable of interest is losses in terms of either U.S. dollars or percent of construction costs. To do this, assembly-based vulnerability is coupled with existing durability data for wood and wood-based products; and when not available, logical assumptions were required. A series of illustrative examples are shown with various mitigation strategies applied to investigate the change in loss fragilities, and subsequently, economic risk if the fragility is recoupled with the flood hazard curve. The method is shown to work efficiently and the results are logical, thus it may find application by aiding developers, land-use planners, engineers, and potentially owners of wood-frame buildings in their design and retrofit decisions.

Silos are special structures subjected to many different unconventional loading conditions, which result in unusual failure modes. Failure of a silo can be devastating as it can result in loss of the container, contamination of the material it contains, loss of material, cleanup, replacement costs, environmental damage, and possible injury or loss of life. Silo damage and failures that occurred in different regions of the world are presented in the paper using illustrative photos. Also provided are a review and discussion of the common or spectacular silo failures due to explosion and bursting, asymmetrical loads created during filling or discharging, large and nonuniform soil pressure, corrosion of metal silos, deterioration of concrete silos due to silage acids, internal structural collapse, and thermal ratcheting. Silo damage and failures from several earthquakes are also presented.

This paper describes the development of analytical models used to predict the response of bonded membrane retrofit concrete masonry walls subjected to out-of-plane impulse pressure loads. Full scale tests have shown significant improvement in the resistance of unreinforced concrete masonry walls retrofitted by membrane materials. The majority of the membrane retrofit concrete masonry walls survived compared to their unretrofitted counterparts that collapsed. Polymer membrane retrofit materials may be sprayed on, trowled on, or attached with adhesives to the tension face of the wall. Other membrane materials such as thin steel or aluminum sheets may be attached to the tension face of the wall using expansion screws or other structurally sound methods. Resistance functions previously presented by the writers for membrane retrofit concrete masonry walls are used in the development of the response. Single-degree-of-freedom equations are developed to predict the response of these walls to impulse pressure and the results of the analysis are compared with available full-scale tests.

This paper describes an arch type steel footbridge, its analytical modeling, modal testing, finite-element model updating, and dynamic analysis. A modern steel footbridge which has an arch type structural system and is located on the Karadeniz coast road in Trabzon, Turkey is selected as an application. An analytical modal analysis is performed on the developed three-dimensional finite-element model of footbridge to provide analytical frequencies and mode shapes. Field ambient vibration tests on the footbridge deck under natural excitation such as human walking and traffic loads are conducted. The output-only modal parameter identification is carried out by using peak picking of the average normalized power spectral densities in the frequency domain and stochastic subspace identification in the time domain, and dynamic characteristics such as natural frequencies, mode shapes, and damping ratios are determined. The finite-element model of the footbridge is updated to minimize the differences between analytically and experimentally estimated modal properties by changing some uncertain modeling parameters such as material properties. Dynamic analyses of the footbridge before and after finite-element model updating are performed using the 1992 Erzincan earthquake record. At the end of the study, maximum differences in the natural frequencies are reduced from 22 to only 5% and good agreement is found between analytical and experimental dynamic characteristics such as natural frequencies and mode shapes by model updating. Also, maximum displacements and principal stresses before and after model updating are compared with each other.

Kömürhan Highway Bridge is a reinforced concrete box girder bridge located on the 51st km of Elazığ–Malatya Highway over the Fırat River. Because of the fact that the Kömürhan Bridge is the only bridge in this part of Fırat, it has major logistical importance. So, this paper aims to determine dynamic characteristics such as natural frequencies, mode shapes, and damping ratios of the bridge using experimental measurements and finite-element analyses to evaluate current behavior. The experimental measurements are carried out by ambient vibration tests under traffic loads. Due to the expansion joint in the middle of the bridge, special measurement points are selected and experimental test setups are constituted. Vibration data are gathered from the both box girder and bridge deck. Measurement time, frequency span, and effective mode number are determined by considering similar studies and literature. The peak picking method in the frequency domain is used for the output-only modal identification. An analytical modal analysis is performed on the developed two- and three-dimensional finite-element model of the bridge using SAP2000 software to provide the analytical frequencies and mode shapes. At the end of the study, dynamic characteristics of the Elazığ and Malatya parts of the bridge obtained from the experimental measurements are compared with each other and transverse effects on the bridge are determined. Also, experimental and analytical dynamic characteristics are compared. Good agreement is found between dynamic characteristics in the all measurement test setups performed on the box girder and bridge deck and analytical modal analyses.

A forensic study was conducted to investigate the premature pavement failure of heaving and cracking on the north bound lane of SH6 and to determine (1) the causes of the heaving and cracking; (2) the severity and extent of the problem; and (3) a prevention strategy. Ground penetration radar (GPR), falling weight deflectometer (FWD), dynamic cone penetrometer (DCP), and soil boring and laboratory tests were conducted. Soil maps provided by the Natural Resource Conservation Service (NRCS) and the electrical resistivity tomography (ERT) were utilized to locate areas that may have similar problems for the ongoing project. It was concluded that the heaving was caused by high organic content in soils. The low pH of the lime treated subgrade layer indicated that the lime stabilization was ineffective. This was due to the high concentration of organic matter. FWD and DCP results indicated that the heaved/cracked areas are losing structural load support. Approximately 84% of the bumps/dips detected by the profiler were also detected by the GPR. Based on the GPR results, it was estimated that about $1.2\text{miles}$ of the roadway may have potential heaving in the future. Although it is not a standard practice to determine the organic content of soil for new construction, it is critical to determine the organic matter through soil boring and laboratory testing in the suspicious areas. It was found that the soil maps provided by the NRCS yielded a reasonable estimate, and can be used as a screening tool. All five locations (O1 to O5) identified by ERT were verified by boring and laboratory tests to have high organic content (1.9–3.3%). Boring results indicated that ERT was able to map the soil strata and could differentiate between sandy and clay soil types. Although ERT was able to identify the anomalies with high organic contents, and the results were confirmed by boring and laboratory testing, additional work is needed to refine the procedure.

Most state highway agencies conduct inventory friction testing on mainline highways to monitor network pavement friction performance. However, no state highway agencies have been reported to monitor pavement friction performance on interchange ramps. Interchange ramps constitute a large portion of the interstate highway facilities. Great concerns have arisen nationwide due to the increasing number of accidents in the ramp areas. This paper presents an effort to evaluate pavement friction performance on interchange ramps in Indiana. It is found that the overall average posted speed is $38\mathrm{mi}∕\mathrm{h}$ on interchange ramps, which is close to the test speed of $64\mathrm{km}∕\mathrm{h}$ recommended by AASHTO for establishing pavement friction requirements. In addition, pavement friction seemed to decrease as ramp curvature decreased. In general, three tests at the entrance, midpoint, and exit can provide information sufficient to evaluate pavement friction performance on an entire ramp. The 15th percentile friction number for overall interstate mainline pavements is 30 and 29 for the selected ramps.

The oldest statue on earth—the $\mathrm{3,300}\text{-}\text{year}$ -old colossus—of Rameses II is going to be transported from a major square in downtown Cairo to a new more-preserving home approximately $30\mathrm{km}$ away. The process of moving the huge granite sculpture is very complicated and has to be thoroughly investigated and carefully planned in order to avoid damage to such a valuable piece of cultural heritage. Determination of the vibration properties of the colossus is of major importance in order to evaluate the effect of the expected excitations from the forthcoming processes. To this end, the application of the advanced modal testing technique serves the process in detecting and assessing the weaker critical regions of the old colossus. This study is the first step in an intended comprehensive modal testing program. The study provides understanding of the distinctions in the basic modal behavior of the historic colossus. It also gives an assessment for the level of vibration this invaluable colossus is currently exposed to. A three-dimensional (3D) finite-element model was built based on accurately surveyed geometry from the site. The solid modeling capabilities of the ANSYS software helped in modeling the complex 3D geometry. Model updating was performed based on the results determined from ambient vibration tests and observations from the site. The updated model correlated well with the vibration test results. It showed the existence of weak areas close to the feet and to the head-to-abdomen conjunction. It also pointed out the degrading of the granite material properties.